allows each business-class customer of ours to include what we are calling "custom fields."

Each custom field has three fields that need to be filled out for maximum operability.

The first is the type of custom field you want to create. You can choose from tel, url, email and note.
The second input is the field that will hold the "label" or "title" of your new field.
The third input is the value of that new field.

Quick Note:

All custom fields wil be added to two places on your vCard. The first is the appropriate field specific to the type you've chosen. The second place it will be added is the "NOTES" section of your vcard. We do this because typically there are only one EMAIL and URL fields shown per vCard (even though it still stores it). So without the custom data being stored in the NOTES section, most people would never see it.